<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    {% block header %}
        here is header<br>
    {% endblock %}
    {% block content %}
        content area<br>
    {% endblock %}
    {% block footer %}
        here is footer
    {% endblock %}
</body>
</html>